If your note-taking, data-collecting app doesn't agree with you, you've got plenty of options out there; as for me, I'm happy with Yojimbo, and happier now that 1.5 is out. The new version adds images as a full-fledged data type (meaning you can sync pictures via .Mac, although you're warned not to try and replace iPhoto or Aperture) and improves search performance. There's also now an auto-update feature, at long last!
You can get the 10.4 MB download here. Note that the update requires a change to your database structure, so it will back up your existing files before it runs.